Excellent, a must-have! Rated 5 out of 5 stars

Using Ver 0.6.6 in TB 3.1.7
This definitely should be included in Thunderbird by default. Anyone using mail clients I think expects this feature.
It functions great, looks good and has simple useability.

It beats FolderPaneTools 0.6 because:
1. Allows for sorting of folders, not just accounts
2. Has same sorting options, but more sort methods
3. Easy to get to sorting in the Tools menu
4. Better GUI, both in look and function

This review is for a previous version of the add-on (0.6.6).